They just get kibble with whatever the "special of the day" is. If it's leftover steamed broccoli, so be it. If it's beef trimmings, awesome. Potatoes, those are good too.
Basically, if it's safe for them, they get it. We eat whole foods made from scratch, and I figure it's good for them to have a variety of whole food too. I should be giving them more fish oil.
Sometimes I buy them a rack of beef ribs or something. Usually they get a couple of raw meals a week for variety/dental health.
They also eat whatever my son throws at them from his high chair. Sigh.